# Multiplier — Predict height & bone length

> Automated orthopedic and growth prediction calculations for children. (iPhone/iPad app by LifeBridge Health.)

- Source: https://appshunter.io/ios/app/multiplier/id460335161 (this page in markdown: same URL + `.md`)
- Developer: [LifeBridge Health](https://appshunter.io/developer/460335164)
- Category: Medical, Health & Fitness
- Price: Free
- Rating: 4.63/5 from 24 App Store ratings · 30 written reviews indexed
- Age rating: 12+
- Requires: iOS 13.0 · 62 MB
- Languages: English
- Released: 2011-09-02
- Data updated: 2026-07-02
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/multiplier/id460335161/reviews.md

## What is Multiplier?

The Multiplier App automates calculations to predict mature height and bone length in children. This method was created originally in Baltimore at the University of Maryland and subsequently developed at the International Center for Limb Lengthening (ICLL), Rubin Institute for Advanced Orthopedics (RIAO), Sinai Hospital of Baltimore.

We have taught the Multiplier Method for more than 19 years at our annual Baltimore Limb Deformity Course (http://www.DeformityCourse.com). These calculations are typically performed by hand, using various formulae. Certain calculations are easy, but others involve more complicated formulae. Utilizing this app will reduce the time needed for these routine calculations and decrease errors. You need only input certain data (sex, age, length) and the app will calculate the answer by using the appropriate Multiplier formula.

The Multiplier App will allow you to make the following calculations: 

LOWER EXTREMITY
   · Limb Length Discrepancy (LLD) (Congenital)
   · LLD (Developmental)
   · Growth Remaining
   · Bone Length
   · Timing of Angular Correction
   · Timing of Epiphysiodesis
   · Comprehensive (Congenital) LLD and Epiphysiodesis
   · Scanogram Calculations (Calculates femur/tibia lengths, overall limb length discrepancy, and amount/side of femur/tibia discrepancies)

UPPER EXTREMITY
   · LLD (Congenital)
   · LLD (Developmental)
   · Growth Remaining
   · Bone Length

Height and CDC Growth Charts (Calculates height at maturity, calculates height at every age, and plots the patient’s height and weight on the CDC growth charts) 

ACHONDROPLASIA
   · Height
   · Sitting Height
   · Leg Length

Fetus (Calculates the length of tibia or femur at birth and maturity) 

FOOT
   · Foot Length
   · Foot Length Discrepancy
   · Foot Height
   · Foot Height Discrepancy

Spine (Calculates sitting height at maturity) 

Oblique Plane Deformity (Calculates magnitude, orientation, and direction of an oblique plane deformity) 

Inclined Osteotomy (Calculates the rotational orientation and the vertical inclination of the osteotomy) 


This app also provides the following additional resources: 

   · Bone Age: Elbow and Hand (Shows how to determine skeletal age by using radiographs of the elbow or hand)
   · Figures that show the standard measurements for the lower limb and foot
   · The multiplier formulae that the app uses to perform the calculations
   · Tables that show the multiplier values that are used in the formulae
   · Figures that show the Solomin Foot Analysis (Deformity correction planning for the midfoot, hindfoot, and ankle using reference lines and angles provided by Dr. Leonid Solomin)
   · Figures that show the development of the apophyses, epiphyses, and bones
   · Bibliography
   · User guide

DISCLAIMER: No growth prediction method is 100% accurate; this App is not a substitute for sound and careful clinical judgment.

PRIVACY POLICY: We respect the privacy of the people who use the International Center for Limb Lengthening apps. The Multiplier app does not collect, use, or distribute any data from the users.

## Key features

- Predict mature height
- Calculate bone length
- Assess limb length discrepancy
- Analyze growth remaining
- Plot height on CDC charts
- Scanogram calculations
- Foot length analysis

## Recent user reviews (10 of 30)

All indexed reviews: https://appshunter.io/ios/app/multiplier/id460335161/reviews.md

### 5/5 — Multiplier the best app for providers!

*2022-07-07, version 7.0*

This app is easy to use, simple and fast In a few seconds I can answer all the questions parents will ask about the predicted height and leg length discrepancy!

### 5/5 — Essential app for peds ortho

*2022-02-20, version 7.0*

This app is imperative for anyone treating limb length discrepancies in the growing child. It can be used to predict final discrepancy magnitude, time epiphysiodeses, predict adult height, and provide an immense amount of clinically pertinent information for patients and providers alike. It comes from pioneers and household names in the field of deformity management, and I would absolutely recommend it to anyone seeing these patients!

### 5/5 — The best for limb length discrepancy calculation!

*2020-12-05, version 7.0*

This is, without a doubt, the absolute best app for anyone who sees patients with limb length discrepancies. Easy to use, reliable, and based on established data.

There is also a wonderful tutorial (on VuMedi) to understand how to use it.

This is a game changer in a busy clinic!

### 5/5 — Awesome app

*2020-01-07, version 7.0*

Can’t live without it in my practice!! Honestly, a must have app for any pediatric orthopedic surgeon.

### 5/5 — Fantastic update!

*2019-09-30, version 7.0*

Very useful update to an already critical App for pedipods. The new bone age section for hand x-Rays is simple to use and efficient. The new CDC growth chart option makes it easy to share graphically displayed data with parents. Thanks for these new tools!

### 5/5 — Good but...

*2019-06-25, version 6.3.1*

Good but my height is gonna b 5 foot 9 when I’m older

### 5/5 — Growth

*2018-10-13, version 6.3*

Help me to get taller and bigger faster

### 5/5 — Essential tool for pediatric orthopaedic surgeons

*2018-08-26, version 6.3*

This is an invaluable tool for practicing pediatric orthopaedic surgeons developed by Drs. Herzenberg and Paley - a must-have free download for all orthopaedic residents and orthopaedic surgeons.

### 5/5 — Lots of fun! Fairly consistent. Hope it's accurate!

*2017-01-29, version 6.0*

I've had this app for several years. I have been tracking both of my daughters and the predictions have been fairly consistent throughout the years. I recently started tracking my infant son as well and I hope the predictions are correct, although I won't know for several years. I am very short and my husband is tall, so it's fun to use this for an idea of how tall my children will grow. Side note: I only use the height predictor. I have not tried the other functions.

### 5/5 — Quick and well designed

*2016-09-12, version 5.0*

As a pediatric orthopedist with a focus in deformity correction, I find this app to be an excellent resource.  Within the limits of the data on which the program is based, I have not found a better resource.  Excellent for quick teaching and calculations in the office setting.

## Frequently asked questions about Multiplier

### What does the Multiplier app do?

The Multiplier app automates complex calculations to predict a child's mature height, bone length, and assess limb length discrepancies. It simplifies manual methods used in pediatric orthopedics and growth assessments, reducing calculation time and potential errors.

### What are the key features of the Multiplier app?

Key features include calculations for limb length discrepancy (congenital and developmental), growth remaining, bone length, timing of angular correction and epiphyseodesis, scanogram calculations, height prediction at maturity, and plotting height on CDC growth charts. It also offers specific calculations for achondroplasia, fetal growth, foot length, spine growth, and oblique plane deformities.

### How much does the Multiplier app cost?

The Multiplier app is a paid application. The provided data indicates it does not have in-app purchases or ads, suggesting a one-time purchase for full access to its features.

### Is the Multiplier app accurate?

While the app automates calculations based on established methods, no growth prediction method is 100% accurate. The app is intended to assist clinical judgment, not replace it. It provides tools for precise calculations that can aid in diagnosis and treatment planning.

### Who is the target audience for the Multiplier app?

The app is designed for healthcare professionals, particularly those specializing in pediatrics and orthopedics, such as pediatricians, orthopedic surgeons, and clinicians involved in assessing and managing child growth and limb development.

## Version history (last 5 releases)

### 10.0 — 2026-07-02

Thank you for using Multiplier! This updated version introduces several exciting enhancements. The redesigned interface offers continuous access to frequently used features, along with a new Foot Height and Foot Height Discrepancy calculator. We'd like to thank Dr. Raymond Liu and his team for helping us with these calculations. To users who are attending our annual Baltimore Limb Deformity Course, Dr. John Herzenberg will be demonstrating what the new Multiplier has to offer. We hope you enjoy!

### 8.0.1 — 2024-05-11

performance improvement. 
keyboard bug fixed for the UK.

### 8.0 — 2024-04-17

Exciting Updates:
We’ve introduced new features for the Ilizarov treatment, located in Additional Resources.
These include comprehensive calculators for both the Ilizarov hinge orientation along with a nut turning prescription after the Ilizarov frame has been applied.
A new calculator interface has been added for iPad users in place of the QWERTY keyboard.
Several bugs affecting calculations throughout the app have been resolved, ensuring more accurate results.

We're committed to continuously improving our app to better serve your needs. Thank you for using the Multiplier app!

### 7.0 — 2019-08-12

We added “Scanogram Calculations” under “Lower Extremity.” After entering the scanogram measurements, the screen will calculate the lengths of the individual femora and tibiae as well as the overall discrepancy for the limbs (using the femoral and tibial discrepancies). It will also provide the amount of each tibial and femoral discrepancy and whether each discrepancy is present on the right side or the left side. Under “Additional Resources,” we have added a new section called “Solomin Foot Analysis” that shows deformity correction planning for the midfoot, hindfoot, and ankle using reference lines and angles provided by Dr. Leonid Solomin. We improved the formatting of the data entry screens to reduce errors when inputting data. For example, units of length (cm or inches) no longer have a default unit selected; the user must choose the unit of length. We improved the formatting of the results screens to reduce errors in interpreting data. The Multiplier has been upgraded to support the latest iOS and improve its performance.

### 6.3.1 — 2018-11-02

We have corrected an issue with a data entry screen.

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## More apps by LifeBridge Health

- [Multiplier HD](https://appshunter.io/ios/app/multiplier-hd/id460343565)
- [Bone Ninja](https://appshunter.io/ios/app/bone-ninja/id554151432)
- [LifeBridge Health](https://appshunter.io/ios/app/lifebridge-health/id1611570941)
- [Bone Ninja Sensei](https://appshunter.io/ios/app/bone-ninja-sensei/id6450483301)

All apps by LifeBridge Health: https://appshunter.io/developer/460335164

## Related topics

[bone age](https://appshunter.io/ios/topics/bone-age) · [femur](https://appshunter.io/ios/topics/femur) · [free height prediction](https://appshunter.io/ios/topics/free-height-prediction) · [illinois bone and joint institute](https://appshunter.io/ios/topics/illinois-bone-and-joint-institute) · [easy bone age atlas](https://appshunter.io/ios/topics/easy-bone-age-atlas)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-02.*